The present disclosure relates to an image forming apparatus such as a copying machine, a printer or a facsimile machine, and more particularly relates to an image forming apparatus that includes a development device and an image carrying member unit which are removably fitted to the image forming apparatus.
In a conventional image forming apparatus, when the number of sheets printed reaches a predetermined number of sheets (for example, several tens of thousands of sheets) due to the life of a photoconductive drum (image carrying member), it is necessary to replace a drum unit (image carrying member unit) including the photoconductive drum. It may be necessary to perform the maintenance or the replacement of a development device arranged adjacent to the drum unit.
Hence, various types of mechanisms that can easily insert and remove the photoconductive drum and the development device are devised; for example, there is known a configuration in which a process cartridge (image formation unit) where a photoconductive drum and a development device are formed integrally is removable from the main body of the image forming apparatus.
There is also known an image forming apparatus having a roller contact/separation mechanism in which after a development device is fitted to the main body of the image forming apparatus, as a holder member (drum locating unit) to which a locating plate for locating the drum shaft of a photoconductive drum is fitted is closed, a development roller is brought into contact with the photoconductive drum, and as the holder member is opened, the development roller is retracted from the photoconductive drum, with the result that when a drum unit or the development device is replaced, the photoconductive drum and the development roller are prevented from being scratched.